There was an error running the selected generator . try rebuilding the project

This is the problem with the connection string you can change the connection string with your DbContext name like bellow on the file web.config:

<connectionStrings>
  <add name="MovieDBContext" connectionString="Data Source=(LocalDb)\v11.0;AttachDbFilename=|DataDirectory|\aspnet-MVCmove-20140616082808.mdf;Initial Catalog=aspnet-MVCmove-20140616082808;Integrated Security=True" providerName="System.Data.SqlClient" />
</connectionStrings>

For the class:

using System;
using System.Data.Entity;
namespace MVCmove.Models
{
  public class Movie
  {
    public int ID { get; set; }
    public string Title { get; set; }
    public DateTime ReleaseDate { get; set; }
    public string Default1Genre { get; set; }
    public decimal Price { get; set; }
  }
  public class MovieDBContext : DbContext
  {    
    public DbSet<Movie> Movies { get; set; }
  }
}

I got this error attempting to build my first Scaffolded item on a newly created project using database first EF.

It's important to Build the Project after adding a new Entity Data Model. Apparently, it's necessary to initialize/configure aspects of the project.

I had read about this previously in a database first tutorial, but had forgotten it. Eventually, I remembered it after digging through related SO issues, including this one.